E8000 loss of power

[electricbogaloo]

From purchase my motor infrequently starts to loose power the assistance gets weaker and sometimes it's completely gone.

It has nothing to do with overheating because it never happens during a steep scent when there is power on the drivetrain but mostly in situations we're I just switched on the system and I pedal on flat ground.

If I power it off and on again it's gone for a few days, hours or minutes. Occurrence is completely random.

Does anybody experience the same behavior?

 

[Hugh-Jazz]

Seems like an intermittently failing torque sensor. Is the motor still under warranty?

 

[electricbogaloo]

Yep. I should have sent it in this winter but I think I'll wait till the off season because it's not much of an issue right now.

 

[R120]

Are you sure the battery mount is tight, and that you have checked the alignment of the speed sensor and magnet. Also check all the connections are properly clicked in on the display, and behind the cover on the LHS of the motor. Sometime the cables are too tightly secured to the frame, so for example, if the swingarm is moving and then sensor cable is too tight, it might pull out.

If the bike is cutting out, but not producing an error code on the display, most times it is a loose connection. When the motor fails you either get an error ode on the display, or it sound like a bunch of ball bearing in a washing machine.

These are the connection behind the motor cover

 

[Hugh-Jazz]

That sounds about right. You could also have dirty battery terminals or connection to the motor.

 

[electricbogaloo]

I was rebuilding the motor in the off season a few weeks ago and checked the cables.

It's also not a clean power cut out immediately. The motor keeps assisting its just that its getting a bit weaker and then stronger again before it cuts out completely. There are no error codes or anything else showing up on the display which stays on.

Maybe it has something to do with the wrong gear like I'm spinning the cranks too fast while going slightly downhill with too much speed. Like the walk assist detects there is no assistance needed.

The description in this review sounds like it's the same issue except I don't have it at the 25kph limit:

While the power delivery was smooth for the most part, there was some very odd surging feedback through the cranks when soft-pedalling or just under the 25kph speed limit. For some reason, the system would cut in and out in a fairly jerky manner, usually as you rotated the cranks through the dead spot.

Shimano STEPS E8000 first ride review

 

[Stuart569]

Having the same issue myself I'm pretty certain it's a failing torque sensor. Haven't seen the power bar go above 50% in a long time and I'm getting loads more miles out of a charge. Funnily enough my average heart rate has about doubled on rides?. No noticeable differance when switching between eco and trail mode either

 

[steve_sordy]

I have been through two wet British winters and the e8000 has had ZERO problems. It was the e8000 motor that persuaded me to buy the Focus Jam2. I liked the bike, but the way the power was delivered by the e8000 was so much better than any other motor I had tested.

Not sure I'm sold on the ep8 just yet. Just been launched and already they have had problems with the design. The motor failed certain EU certification tests (something to do with fatigue life). All the existing motors fitted to bikes for launch have been held back. The production lines will need retooling. Not sure what they are going to do with existing stocks, because they are not designed to be taken apart.....

 

[Jun]

I was rebuilding the motor in the off season a few weeks ago and checked the cables.

It's also not a clean power cut out immediately. The motor keeps assisting its just that its getting a bit weaker and then stronger again before it cuts out completely. There are no error codes or anything else showing up on the display which stays on.

Maybe it has something to do with the wrong gear like I'm spinning the cranks too fast while going slightly downhill with too much speed. Like the walk assist detects there is no assistance needed.

The description in this review sounds like it's the same issue except I don't have it at the 25kph limit:



Shimano STEPS E8000 first ride review

Hi I have ep8 and have the same problem. Mostly on flat it reduces power and stop pushing making my feet heavier. Stopping and restart ing pedaling the motor pushes again. It happens in eco but once it happens changing to trial or boost doesn't make difference.
Do you still have the problem or did you solve it?

 

[electricbogaloo]

Yeah, still have it. Didn't get worse or anything. Just showes up once in a while but not really often, so I restart the system and everything works fine again.